Experimental evaluation of cyclic performance of steel slag and grids of truck scrap tire as a novel reinforced ballast material

Abstract

Introducing a novel ballast material based on reinforcing steel slag aggregates with strips of scrap tire can be beneficial due to decreasing the crushing and increasing the damping of the ballast materials. Moreover, recycling the two waste materials included in this novel ballast has a positive impact on environmental preservation. In this regard, the Waste Tire Reinforcement (WTR) consists of strips of truck scrap tire (385/80/R22.5) with a width of 70 mm utilized in grid shape (with various dimension grids of 21 ×7, 11.5 ×7, and 7 ×7 cm) as a reinforcement element. To evaluate the performance of suggested reinforcement with Steel Slag Ballast (SSB), a series of ballast box tests were performed up to 100,000 loading and unloading cycles with a magnitude and frequency of 30 kN and 3 Hz at three different levels of 5, 10, and 15 cm for WTR placement in ballast. The experimental results revealed that the WTR reinforcement with grids of 11.5 × 7 cm and a placement height of 5 cm (WTR11.5–5) has the best performance compared to other configurations. Compared to SSB without reinforcement, WTR11.5–5 may reduce breakage by more than 90% and increase the damaging ratio by 160%.